docs: def entrance_beveled(Di, l, angle, method='Rennels'):
      r'''Returns loss coefficient for a beveled or chamfered entrance to a pipe
      flush with the wall of a reservoir. This calculation has two methods
      available.
      
      The 'Rennels' and 'Idelchik' methods have similar trends, but the 'Rennels'
      formulation is centered around a straight loss coefficient of 0.57, so it
      is normally at least 0.07 higher.
      
      The Rennels [1]_ formulas are:
  
      .. math::
          K = 0.0696\left(1 - C_b\frac{l}{d}\right)\lambda^2 + (\lambda-1)^2
  
      .. math::
          \lambda = 1 + 0.622\left[1-1.5C_b\left(\frac{l}{d}
          \right)^{\frac{1-(l/d)^{1/4}}{2}}\right]
  
      .. math::
          C_b = \left(1 - \frac{\theta}{90}\right)\left(\frac{\theta}{90}
          \right)^{\frac{1}{1+l/d}}
  
      .. figure:: fittings/flush_mounted_beveled_entrance.png
         :scale: 30 %
         :alt: Beveled entrace mounted straight; after [1]_
  
      Parameters
      ----------
      Di : float
          Inside diameter of pipe, [m]
      l : float
          Length of bevel measured parallel to the pipe length, [m]
      angle : float
          Angle of bevel with respect to the pipe length, [degrees]
      method : str, optional
          One of 'Rennels', or 'Idelchik', [-]
  
      Returns
      -------
      K : float
          Loss coefficient [-]
  
      Notes
      -----
      A cheap way of getting a lower pressure drop.
      Little credible data is available.
      
      The table of data in [2]_ uses the angle for both bevels, so it runs from 0
      to 180 degrees; this function follows the convention in [1]_ which uses
      only one angle, with the angle varying from 0 to 90 degrees.
  
      .. plot:: plots/entrance_beveled.py
  
      Examples
      --------
      >>> entrance_beveled(Di=0.1, l=0.003, angle=45)
      0.45086864221916984
      >>> entrance_beveled(Di=0.1, l=0.003, angle=45, method='Idelchik')
      0.3995000000000001
      
      References
      ----------
      .. [1] Rennels, Donald C., and Hobart M. Hudson. Pipe Flow: A Practical
         and Comprehensive Guide. 1st edition. Hoboken, N.J: Wiley, 2012.
      .. [2] Idel’chik, I. E. Handbook of Hydraulic Resistance: Coefficients of 
         Local Resistance and of Friction (Spravochnik Po Gidravlicheskim 
         Soprotivleniyam, Koeffitsienty Mestnykh Soprotivlenii i Soprotivleniya
         Treniya). National technical information Service, 1966.
      '''
      if method is None:
          method = 'Rennels'
      if method == 'Rennels':
          Cb = (1-angle/90.)*(angle/90.)**(1./(1 + l/Di ))
          lbd = 1 + 0.622*(1 - 1.5*Cb*(l/Di)**((1 - (l/Di)**0.25)/2.))
          return 0.0696*(1 - Cb*l/Di)*lbd**2 + (lbd - 1.)**2
      elif method == 'Idelchik':
          return float(entrance_beveled_Idelchik_obj(angle*2.0, l/Di))
      else:
          raise ValueError('Specified method not recognized; methods are %s'
                           %(entrance_beveled_methods))